import javax.crypto.Cipher;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.SecretKeySpec;
import java.security.KeyFactory;
import java.security.PrivateKey;
import java.security.spec.PKCS8EncodedKeySpec;
import java.util.Arrays;
import java.util.Base64;
import java.nio.charset.StandardCharsets;

/**
 * 分析tn字段，看看能否找到线索
 */
public class AnalyzeTN {
    
    private static final String EP_BASE64 = "qt0AJsNLEfayUx7S15jLfmQvMOpW6JJ+jCoxeXxn676R2OiN6xpLIQWSYe8ETFUF4+AaGrVY1wMCdyUPVaHM0J+8m+q/PUFgbiP3N8xSKQc4lIzzZuckbybYiFuLbEhcblmy162S5B70UJxzB6grhIVpsG/h0uw+JPaS2yTPpPVCiN/SImdOw2g12cun6niAwRZSQktZikzzbjwkRoiO8ehrwlAFJircnT1/1zba2oaGXLc/yU6cM2vWgJdyyoXJF4Mo/5XNBTDT+8yr1hPC5MKHWcTBB/isrRTD5CczInLgXHl48KKz18GkpPM7MML1GHb4pIjfTvu8hv/SLLW0sg==";
    
    private static final String TN_BASE64 = "BMWDCPVx97y89WVt17r3tRsHvAaJGgWmfWBdrcS6bNEf6quwgvnvaNhbWBRPqoiARIPp85YYPh/p2Tql88H0Ig==";
    
    private static final String PRIVATE_KEY_PEM = 
        "MIIEvAIBADANBgkqhkiG9w0BAQEFAASCBKYwggSiAgEAAoIBAQCz8JyumzBRR1nj" +
        "dxPzCFpqWXrAUBiC4ycTbTDdWdpZkciwiXU5s/OxF5i7l+Hvwc9Ggjph/PKo7PpW" +
        "hxZpzyEGpd6yVN9jAjJOt23o2TesgK8L/DAMhdJL8gNxKAQumbGF+ebMbcS8jWLx" +
        "vDAqpmnEW8VdCLEjF6uqOPtcDmIkBF83W6oaeu32DzTr/NS16sUGQKxlflo9qPOl" +
        "7VtcIsbR52klKK4uIyY23tWCouiyG84c/Uit+PleD5EYUGEu3p7IAAG5uJNzeUd0" +
        "UjZDhy6x7ue+kGgcCmCNQ4zSS/bQHMknalwqJUvUSxtIf8dq+/D78m7d4Zt9n9ZD" +
        "27t4Z2jHAgMBAAECggEAAr15RVdrpvE1NzeLADpyVghCzEbr+KJI6AzTn6tMneyQ" +
        "Z8/QDy7kWSAI3WJ0uFf1Nhepl/BoKZZiQYsRFk9nK1i/SWvtcu6HoZc9fzw/ksrq" +
        "333ZpXcsOqfW0ZRQa/0/LNEfaKGLS2vDw/afrSaXmbvkB4SoXeZwYMk5Wq+FYxL/" +
        "alrNpg/lzdvBlsCsTDA0G2RZrUVaO5yRTLRisBU+i8yORgnGkEwWvKpZYSFogCHS" +
        "iYHiNXFy//C+sYWlK7DjmG8/+krKhqBRRfdeg7LFThHQpbEGTtueD57jw0PCo2yr" +
        "6dqTvW9Qys+aWVNJk7RHNaI0yBFKWPadaHi3/olzkQKBgQDmz/FDpztS0fjKDIOj" +
        "gDyE76Z6dRFenmKJM1eOFt+MniY6/vi4ylU51/Etm4k6dNJ1MVBoFfyT9X0U/4k7" +
        "GNNUfIxMCJztUgY6EaCCt+09wk8pIvmOlRCmtxGwvmVC4nJVgUj3XJQ+wseblAkk" +
        "W0+IuT3GKX0CdKFMU4q9aucLYwKBgQDHk3rQ8Ae4ci4oj+MehRI29SNpcXG6OHbr" +
        "Z2EdsgqiFC1o/qv0269jtmCP7IqkGMdhTQrVetTHjZNZJH2bvUZ4o/0YT2+TTFPI" +
        "kTb2/a0txUTBTKrbnAdXh/iPFZAGvBROEDN0MNKo/vGAfi0K836DeTyBIaYongm6" +
        "6Rn6pwnUTQKBgBveVaougfoxAhIbSrWuISCH8xjsE6nSA+G/Aj5Uwq8u1TzgVlWx" +
        "kHLIgQVZt0sImfSufJ/kr7eJt42WgRJSoAmedC4mCBSbh8bxI+lEne+MC5TS9UDi" +
        "/Ly0c/1cL8vQna93ScEcO4YMbJ97U1NBdyvx+eR4U/C89lDJ8YGHa9gzAoGAQ6sY" +
        "sHFCXOKyDeTDoFyEUYgKqrzhT7/HaofR4Oy2OEBZKUl4anx2WnvC/+m3FG6mY7Jo" +
        "ovuT29mABXCe+khR9aO8tBpy/WGa4t2B4nse1e8WIehp4i5kOuSKfZFVFUN+Kv3J" +
        "RHMtakmO/v9JLHZlBhT8U9hh61GygOJ6gYdTiN0CgYAFz9iPy/xqLOUwiTNp3Imz" +
        "hdZo9ol3Qlr9CfMWMFHqRA5AyYvly9ZzxTpUCpSA+qz6OXqAjJ0bhGQxW2KHpmcT" +
        "yNGOPPca2vCaW8Mb1NTQueXpUBqX7alIkrRjUUyULteLb8FtyYl7mR3TVIu3FoO5" +
        "anNwDZ+2y7R9WUEiOzY3NA==";
    
    public static void main(String[] args) {
        try {
            System.out.println("=" + "=".repeat(99));
            System.out.println("分析TN字段");
            System.out.println("=" + "=".repeat(99));
            
            // 解密ep获取AES密钥
            byte[] epEncrypted = Base64.getDecoder().decode(EP_BASE64);
            byte[] privateKeyBytes = Base64.getDecoder().decode(PRIVATE_KEY_PEM);
            PKCS8EncodedKeySpec keySpec = new PKCS8EncodedKeySpec(privateKeyBytes);
            KeyFactory keyFactory = KeyFactory.getInstance("RSA");
            PrivateKey privateKey = keyFactory.generatePrivate(keySpec);
            
            Cipher rsaCipher = Cipher.getInstance("RSA/ECB/NoPadding");
            rsaCipher.init(Cipher.DECRYPT_MODE, privateKey);
            byte[] epDecrypted = rsaCipher.doFinal(epEncrypted);
            
            // 尝试不同位置的密钥
            byte[][] keyOptions = {
                Arrays.copyOfRange(epDecrypted, 0, 32),  // ep[0:32]
                Arrays.copyOfRange(epDecrypted, 1, 33),  // ep[1:33]
            };
            
            String[] keyNames = {"ep[0:32]", "ep[1:33]"};
            
            byte[] tnWithIV = Base64.getDecoder().decode(TN_BASE64);
            byte[] tnIV = Arrays.copyOfRange(tnWithIV, 0, 16);
            byte[] tnEncrypted = Arrays.copyOfRange(tnWithIV, 16, tnWithIV.length);
            
            System.out.println("\nTN总长度: " + tnWithIV.length + " 字节");
            System.out.println("TN IV (前16字节): " + bytesToHex(tnIV));
            System.out.println("TN 密文长度: " + tnEncrypted.length + " 字节");
            
            for (int i = 0; i < keyOptions.length; i++) {
                System.out.println("\n" + "-".repeat(100));
                System.out.println("尝试密钥: " + keyNames[i]);
                System.out.println("密钥: " + bytesToHex(keyOptions[i]));
                
                try {
                    Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
                    cipher.init(Cipher.DECRYPT_MODE, new SecretKeySpec(keyOptions[i], "AES"), new IvParameterSpec(tnIV));
                    byte[] tnDecrypted = cipher.doFinal(tnEncrypted);
                    
                    System.out.println("✅ TN解密成功！长度: " + tnDecrypted.length + " 字节");
                    System.out.println("\nTN解密后的数据:");
                    System.out.println("HEX: " + bytesToHex(tnDecrypted));
                    
                    // 尝试作为UTF-8字符串
                    try {
                        String tnString = new String(tnDecrypted, StandardCharsets.UTF_8);
                        System.out.println("\n作为UTF-8字符串:");
                        System.out.println(tnString);
                    } catch (Exception e) {
                        System.out.println("\n无法作为UTF-8解析: " + e.getMessage());
                    }
                    
                    // 检查是否包含data的IV
                    if (tnDecrypted.length >= 16) {
                        System.out.println("\n检查是否包含data的IV...");
                        byte[] possibleDataIV = Arrays.copyOfRange(tnDecrypted, 0, 16);
                        System.out.println("TN前16字节: " + bytesToHex(possibleDataIV));
                    }
                    
                } catch (Exception e) {
                    System.out.println("❌ TN解密失败: " + e.getMessage());
                }
            }
            
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
    
    private static String bytesToHex(byte[] bytes) {
        StringBuilder sb = new StringBuilder();
        for (byte b : bytes) {
            sb.append(String.format("%02x", b));
        }
        return sb.toString();
    }
}


